This invention relates to squeegees of the type employed, for example, in screen printing apparatus, and more particularly to an improved such squeegee and blade holder therefor.
It has long been a custom to employ in screen printing apparatus and the like, a squeegee in the form of an elongate rubber blade or the like, which is secured adjacent one marginal edge thereof in a recess in a holder or pair of jaws which can be manipulated to sweep the other edge of the blade along the surface of the screen which is employed for printing purposes. In one such prior art squeegee the handle is made from an elongate piece of wood having an elongate, rectangularly-shaped notch or recess in its lower edge, and with a rubber blade secured adjacent one elongate edge thereof in a recess by staples. In U.S. Design Pat. No. Des. 214,085, a two-piece squeegee is formed by an elongate handle having in one longitudinal edge thereof a nearly circular recess which opens on the bottom of the handle, and which releasably secures therein one longitudinal edge of a rubber blade which has formed thereon a slightly enlarged, nearly circular embossment which is slightly mounted in the circular recess in the bottom of the handle.
In U.S. Pat. No. 5,321,868, an elongate, rigid handle which is rather convexedly shaped along its upper edge, has at its lower edge an elongate, generally rectangularly-shaped notch in which one, correspondingly-shaped edge of a rubber blade is secured frictionally or with adhesive in the rectangular recess in the bottom of a handle. In U.S. Pat. No. 4,276,826, one edge of a rubber blade is secured between a pair of jaws which are carried by screen printing press, and in U.S. Pat. No. 4,047,480 one edge of a rubber blade is secured between two elongate, metal straps which are secured to opposite sides of the blade by a pair of clamps. The blade of U.S. Pat. No. 4,047,840 differs from that disclosed in U.S. Pat. No. 5,321,868 to the extent that its lower, operating edge is generally V-shaped in cross-section, thus presenting one edge for webbing, while the lower edge of the blade in the U.S. Pat. No. 5,321,868 is rectangular in cross-section presenting two spaced, parallel edges either of which can be employed as an operating or wiping edge.
Among the major disadvantages of prior such squeegees is that as a general rule, the blades are extremely difficult to remove from the associated holder to permit the blade to recover chemically and/or physically to its original, for example urethane state, after prolonged use. Moreover most assemblies require tools for mounting the blade in or removing it from an associated handle so very often the blades are seldom if ever removed from the associated handle, and it makes the clamped edge unusable.
In practice, the principle of a squeegee blade is to wipe or screen print on one of the two spaced, parallel lower edges of the blade of the type referred to in above-noted U.S. Pat. No. 5,321,868, or along the one pointed edge the type disclosed in U.S. Pat. No. 4,047,484. Squeegee blades also, typically, are made with different durometers, typically from 50 to 95 durometer. They therefore are flexible in use. Unfortunately, one of the disadvantages of prior art such blades associated handles is the fact that a major portion of the blade projects from or beneath the handle, so that during use, more pressure on the blade results in a dramatic tendency of the blade to flex during use, so that it no longer scapes the printing ink, but instead undesirably plows the ink.
It is an object of this invention, therefore, to provide an improved squeegee comprising a recessed blade holder, and novel means for releasably securing a squeegee blade in the holder.
Still another object of this invention is to provide an improved squeegee of the type described which enables a squeegee blade to be releasably inserted into and removed from its associated holder without the need for employing any special tool.
Still another object of this invention is to provide novel means for releasably securing a squeegee blade in an elongate recess formed in one edge of a blade holder by inserting a portion of the blade along one edge thereof in the holder, and by releasably press fitting a pair of elongate locking rods in shallow recesses formed in the holder at opposite sides of the blade releasably to secure the blade in the holder.
A further object of this invention is to provide a squeegee of the type described in which a substantial portion of a squeegee blade, for example up to 75% thereof, is seated and secured in the recess in the blade holder to minimize the amount of undesirable flex which otherwise occurs with known squeegees during use.
Other objects of the invention would be apparent hereinafter from the specification and from the recital of the appended claims, particularly when read in conjunction with the accompanying drawing.